Animal experts fear the possibility of foot-and-mouth in the national deer herd could hamper efforts to eradicate the disease by slaughtering farm livestock.

Tests are being carried out on two roe deer found dead in Cumbria with lesions around the mouth.

Regional veterinary officer for Cumbria, Andrew Hayward, said the symptoms meant the deer could be victims of the disease which has led to the destruction of 1,974,000 animals.

The more you chase wild deer around the country the more they run around

Andrew Hoon, Deer Initiative

The possibility of foot-and-mouth spreading to the UK's 1.5 million deer population, which is mainly free roaming and difficult to isolate, is described as "very serious".

Chief veterinary officer Jim Scudamore said tests on suspect deer in Devon and Cumbria had proved negative, but investigations were continuing.

Dr John Fletcher, an adviser to the British Deer Society, said he would be astonished if the animals thought to be infected did not have the disease.

Deer 'susceptible'

"I do think the circumstantial evidence and clinical signs are totally convincing," he told BBC Radio 4's Today programme.

"It is not entirely surprising - deer are a susceptible species."

Dr Fletcher said it would be a very serious situation if the virus was capable of spreading from deer to deer in the wild or from deer to livestock.

Deer are widely spread around the UK

The British Deer Society has called for a full forensic cull in affected areas, with tests on fresh carcasses rather than deer which have been found dead.

The deer population is spread widely across the UK but the society estimates there are very few areas of 10 square kilometres where there are no deer.

The main concern is how to control an epidemic in the deer population.

Historic herds

Scientists at the Pirbright laboratories in Surrey have told the Ministry of Agriculture (Maff) that shooting deer, and therefore dispersing the herd, would cause more problems than leaving infected animals in the wild.

Mr Scudamore said the advice was that the virus would go through the deer and they should not become carriers.

Andrew Hoon, chairman of the Deer Initiative, the government's advisory body on deer in England, said there was "no effective way of eliminating them".

He added: "The more you chase wild deer around the country the more they run around. It's impossible. An epidemic would be a very serious situation."

Three of London's Royal Parks were shut to the public for a short period at the start of the foot-and-mouth crisis to stop the disease spreading to the historic deer herds.

William Weston, chief executive of the Royal Parks Agency, has said he was not persuaded his agency's parks at Richmond, Bushy Park and Hampton Court should be closed to the public once more.

"It seemed to us, given the balance of probability, that the risk was a very fine one, and we have to take into account the effect on the locality and to small businesses," he added.